100 is Turbo Reversing options(1/2second press) as follows: Turbo--->Strobe--->Batt Check (1-8 with 8 being full) ---> Bike Indicator Strobe
To enter configuration mode, quickly momentarily press (do not click) the button 15+ times until it starts to flash when held on. Once it starts to flash, you are in configuration mode.
Once in configuration mode, the light will give a solid flash between 1 and 5 times. The number of solid flashes indicates the option number to be changed. To select/change the option turn the light off and back on during the strobing flashes that immediately follow the solid flashes. For instance, when you choose option 1 it will start to flash 1-8 times, turn off and back on after the number of the group you want comes up. When setting the temperature control the light will go from programming to turbo, turn the light off when it reaches the temperature you desire.
1. Mode Group Select. 2. Memory Toggle. 3. Mode Order Toggle. 4. Temperature Calibration Mode. 5. Reversing Toggle.